PUNCH was engaged by MDY construction as Design & Build partners on behalf of Bord na Mona for a 4,300m² composting facility at their waste plant in Drehid, Co. Kildare.

The purpose of the facility is to take organic waste and treat it so that it becomes a usable end product for agriculture. The plant is capable of processing 25,000 tonnes per year of biowaste from households, food waste from the service industry and other commercial biowaste.

When the waste material comes to the facility it is treated in one of twelve composting tunnels in the facility, measuring approx. 5m wide x 5m high x 25m long. These tunnels are cast in concrete with a network of pipes cast into the floor providing a passage for air which is pumped into the compost mix to aid the aerobic digestion process.

The design of the concrete is of a particularly high specification, which is required in a moist environment of with high levels of Ammonium Ions and Ammonium Sulphate at elevated temperatures. There is also a requirement for high mechanical durability, due to the high wear and tear aspect of the site operations.

The main building frame si structural steel which had to be treated for corrosion protection in a severe environment generated by the composting process. The project incorporated green roofs to minimise water attenuation requirements and a grey water-recycling system to reduce water demand.